Four-way switches are used to control lighting from three or more locations. Four-way switches are used in combination with 3-way switches. There are four terminals that provide two sets of toggle positions on a 4-way switch. Each set of terminals is one of the toggle positions. When the switch is in the up position, the current can flow through two terminals. In the down position, the current flows through the other two terminals.
source/image: The Engineering Mindset
How to wire 4 way light switch and intermediate switch, in this video we explain how four way intermediate switching works to connect a light fitting which is controlled with three or more light switches. We look at the EU colour coding wires and explain the different ways to connect the lighting circuit.
source/image: The Engineering Mindset
Remember, four-way switches only work if they’re installed in the circuit in between two three-way switches. You can have as many intervening four-way switches as you want in the lighting control circuit, but they have to be bookended by two three-way switches.A “4-way” (intermediate) switch is a purpose built double pole, double throw (DPDT) switch, internally wired in manufacture to reverse the connections between the input and output and having only four external terminals.
Advertisement
This switch has two pairs of “traveler” terminals that it connects either straight through, or crossed over (transposed, or swapped). An intermediate switch can, however, be implemented by adding appropriate external wiring to an ordinary (six terminal) DPDT switch, or by using a separate DPDT relay.
By connecting one or more 4-way (intermediate) switches in-line, with 3-way switches at either end, the load can be controlled from three or more locations. Toggling any switch changes the state of the load from off to on, or from on to off.In alternative designs, low-voltage relay or electronic controls can be used to switch electrical loads, sometimes without the extra power wires.Disclaimer: Don’t try this at home, electricity is dangerous.
